Hemstitch attachment for sewing machines



April 21, 1931. 5. J. ROUNDS HEMSTITCH ATTACHMENT FOR SEWING MACHINES Filed Feb. 28, 1929 1 ZIHUGWLI O1,

Z6 Z2 7 26 6 Z 7 F 7 Samuel J Rounds Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE SAMUEL J. ROUNDS; F PERIH'AMBOY, EW JERSEY, ASSIGNOR T0 THESINGER' MANIL- FAGTURING COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION JERSEY Application filed. February 28,, 1929.

tendency of the sewing ma chine feeding mech-- anism to feed the under ply of fabric faster than the upper ply and will enable two pieces of fabric of equal length to be stitched to gether without a puckering or gathering of either ply relative to the other. A further object of the invention is to provide a hemstitch attachment of simple and inexpensive construction.

To the attainment of the ends in view, the attachment is constructed with a pressermember and a ply-separator, both preferably carried by a common shank adapted for attachment to the sewing machine-presser-bar in lieu of the regular sewing machine presserfoot. The ply-separator is formed with the usual needle-aperture and thread-slot but differs from known hemstitch attachments in having its upper surface stepped or provided with a shoulder extending transversely of the thread-slot in advance of such slot, that is, at or in advance of the needle-aperture,

the purpose of such shoulder being to hold the upper ply of fabric at an angle to the under ply until it is penetrated by the needle and permit the upper ply to be drawn down into spaced parallel relation with the under ply when the stitch is tightened. This provision is found to compensate for the tendency of the regular sewing machine feed-dog to full-in the under ply and enables the superposed plies of fabric to be loosely stitched to gether without a gathering or puckering of either ply relative to the other.

In the accompanying drawings, Fig. 1 is a front. elevation of a hemstitch attachment embodying the invention; such attachment being shown in working relation with the associated parts of a sewing machine. Fig. 2 is a left side elevation of the same. Fig. 3 is a top plan view, Fig. 4 a rear elevation and Fig. 5 abottom plan view of the attachment. Fig. 6 is a vertical section through the attachment in the line of seamformation, prior to the penetration of the Work by the sewing machine needle. Fig. 7

HEMSTITOH ATTAGHMEN T FOR SEWING MACHINES Serial No. 343,531.

is a similar view after the stitch has been formedand tightened, and Fig. 8 is a view of a sample of work produced by use of the attachment.

Theattachment, in its preferred embodi- 1 ment, is constructed entirely of sheet-metal and comprises a shank 1 formed with bent arms 2 separated by a slot- 3 for the usualpressenf'oot thumb-screw 4 by which the attachment is secured to the presser-bar 5 of a sewing machine having the usual reciprocating needle 6, throat-plate 7 and feed dog 8.

Pivot-ally mounted at 9 upon the clownward extension 10 of the shank 1: is the presser-member 11 which has freedom for a limited rocking movement about the pivot 9. This provision allows the presser-member to press the work squarely and evenly uponthe feed-dog and insures an even feeding action of. the sections of the feed-dog at opposite sides of the line of seam-formation.

Extending laterally from the shank 1 is an arm 12'to the downwardly curved end 13 of which is riveted at 14 the shank 15 of an arn1 16 which extends across the line of seam-formation'and' has tightly clamped and fixed around its free end-porti0n 17 the horizontal U 'fOldedsheet-metal ply-separator 18. The rear edge 19, Fig. 2, of the lower leg of the U-folded piece'is even with the rear edge 20 of the arm 16, while the rear edge 21 of the shorter upper leg of the U- folded piece is disposed about a stitclrlength in advance of the edges 19', 20, giving to the upper side of the ply-separator a stepped formation; the edge-21 constituting a shoulder in advance of and transverse to the thread-Slot 22 which leads rearwardly from the needle-aperture 23. i

The ply-separator, constituted by the parts 17., 18, is thus disposed in advance of the presser-member 11, with a gap 24, Fig. 5, between them, permitting an upper ply u of fabric to pass over the ply-separator, down through the gap 24 and under the pressermember. A. lower ply of material 6 passes straight under the-ply-separator and pressermember. v

It will be observed that the portion a, Fig,

on NEW 6, of the upper ply u of material over the stepped port-ion of the ply-separator is supported at an angle to the under ply 0 prior to penetration by the needle 6. This angular disposition of the upper ply at the stitching point slightly increases the length of fabric of the upper ply incorporated in the stitch and compensates for the well known tendency of the feed-dog to full-in the lower of a plurality of plies, resulting in a seam in which the plies are evenly fed with no puclrering or gathering of either ply relative to the other.

When the stitch is tightened, the upper ply will be drawn down into engagement wit the upper flat surface 25, Fig. 7 of the stepped portion of the ply-separator, before the previous stitch has passed beyond the control of the ply-separator, thus preventing the robbing of thread from the previous stitch by the action of the sewing machine take-up in tightening the stitch being formed.

The locking points 26 ot the stitches 27 should preferably be located at the under side of the work by suitably setting the upper and under thread-tensions, as will be obvious to those skilled in the art.

It will be understood that for purposes of illustration the thickness of the plies of fabric relative to the parts of the hemstitch attachment is considerably exaggerated, the fabric, in reality, being proportionately much thinner than shown.

The present construction has the novel advantage of presenting the upper and lower plies of fabric at different angles to the needle path while permitting the plies to be stitched together in a definite spaced parallel relationship.

Having thus set forth the nature of the invention what I claim herein is:

1. A hemstitch attachment for sewing machines comprising a presser-member and aply-separator disposed in advance of the presser-member and having a thread-slot and a stepped upper surface.

2. A hemstitch attachment for sewing machines comprising a presser-member, and a ply-separator having a fiat under surface and stepped upper surface.

3. A hemstitch attachment for sewing machines comprising a presser-member, and a ply-separator having a needle-aperture and a thread-slot leading from the needle-aperture toward the pressure-member, the upper and lower surface-portions of the ply-separator at the sides of the thread-slot being substantially parallel, and means on said ply-separator for holding the upper ply of fa ric above said upper surface-portion prior to penetration by the sewing machine needle, said means permitting the upper ply of fabtie to be drawn down to said upper surfaceportion when the switch is tightened.

4. A hemstitch attachment for sewing m chines comprising a presser-m ply-separator a thread-slot ex ture toward the presser-m having its upper surface shoulder exte thread-slot in a 5. A hemstitc chines comp separator ha slot leading presser-membe ing upper s h said thread-slot, and means 0 ng the upper p aperture and from the needle-aperember, and also formed with a nding transv dvance of the latter.

h attachment for sewing mamember, a plye and a threadhole toward the separator a tiguous to rising, a presserving a needle from the needler. said plytace portions con u said ply-seply of material an angle to said arator for holdi out of contact with and at surface portions.

In testimony w me to this specsification.

hereof, I have signed my J. ROUNDS. 

